SiUS281117
Troubleshooting by Remote Controller
124
Service Diagnosis
2.16 Heat Exchanger (Liquid pipe) Thermistor Abnormality
Remote
Controller
Display
C4
Applicable
Models
All indoor models
Method of Error
Detection
The error is detected by temperature detected by heat exchanger thermistor.
Error Decision
Conditions
When the heat exchanger thermistor becomes disconnected or shorted while the unit is running
Supposed
Causes
Defective thermistor for heat exchanger (liquid pipe)
Defective indoor unit PCB
Troubleshooting
Note:
Connector and indoor unit PCB
Connector is
connected to the
connector (
∗
) of the
indoor unit
PCB.
Resistance
is normal when
measured after
disconnecting the thermistor
from the indoor unit
PCB.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
CHECK 5
Replace the indoor unit PCB.
Connect the thermistor and turn
ON again.
NO
NO
Replace the thermistor (
∗
).
YES
YES
Model
Connector for the heat exchanger (liquid pipe) thermistor
Electric
Symbol
PCB
FCQ
X18A
R2T
A1P
FHQ
X12A
R2T
A1P
FAQ
X18A
R2T
A1P
FBQ
X18A
R2T
A1P
FTQ
X18A
R1T
A1P
CHECK 5